Heretofore, laminates have generally been prepared from similarly colored layers.
With regard to integral fuel tanks, they have also been made from one or more layers of a clear or identically colored elastomer layer such as a polyurethane.
A polyurethane which has been utilized as a coating for a rubber-fabric fuel tank is set forth in U.S. Pat. No. 4,247,678 to Chung. However, if more than one layer was applied, only one similar color was utilized. Furthermore, Chung does not relate to any in situ formation of a fuel tank, or an article. The components of the Chung formulation have poor stability in that the component other than the amine curative component would start to react with itself or crosslink with the isocyanate therein and thus generally had to be utilized within a week after preparation thereof.
Heretofore, other integral fuel tanks have generally been made of metal structures wherein sealing materials have filled openings, cracks, and the like, with the apparatus then being bolted closed. Such apparatus required tedious, laborious and costly preparation and may be used as a back-up system in the present invention.
Although the present invention utilizes a polyurethane having an overall formulation which is generally similar to the formulation set forth in Chung, U.S. Pat. No. 4,247,678, it relates to the application of contrasting layers to form an article, as for example an in situ article, as well as to various separate components which form the overall polyurethane formulation, the components of which have unexpected and very long shelf life of a matter of months and even years.